(BLOOMINGTON, IN) - Investigators have determined that Crystal Grubb, whose decomposing body was found in a northern Monroe County cornfield was murdered.

Monroe County Sheriff's Office Chief Deputy Mike Pershing says investigators are looking for a male witness who was driving a small red car in the area of North Showers Road on the evening of September 18th.

Crystal Grubb

Grubb's body was discovered by a farmer on October 1st, nearly two weeks after being reported missing.

Police say that Grubb was walking with a group of friends along Old Highway 37, just south of the four-lane highway 37.

Grubb is believed to have got in an argument with her friends and walked away from the group.